Arp Quartet cheap?

Harry Bissell harrybissell at
Fri Nov 5 08:20:16 CET 1999

Its no secret whats inside the top octave generator... its just digital dividers
that have the 12th root of 2 relationship to each other. If anyone has the data
sheet it will tell what the division ratios are... A PLA FPGA etc could do this, or
even good old CMOS logic. An 8 bit divider would give acceptable accuracy in most
cases... more bits are better.
Somewhere in the junk drawer I have an old paper that has some best fit ratios. I
could find it... interest ????

:^) Harry

patchell wrote:

>     Somewhere in my junk box I should have one of those suckers.  If somebody
> needs one to restore an old piece of equipment, I could see if I could find it.
> I have no idea what condition it might be in, or even if I could find it.
>     -Jim
> WeAreAs1 at wrote:
> > Rory McDonald wrote:
> >
> > <<There is an Arp Quartet on eBay (not mine, I just noticed it), not working
> >
> > (no sound output, but everything else looks ok-opamp?) -could be a bargain
> >
> > for a DIY'er.>>
> >
> > ...or it could wind up as another white elephant in the attic, if its top
> > octave divider chip has gone bad.  As far as I know, these chips are not
> > available anywhere anymore.  They are a common point of failure in string
> > ensembles.  If anyone knows where they can be purchased, please let the list
> > know.  (Mostek 50240 and variations thereof)
> >
> > Michael Bacich
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